1. Technical Field
The present disclosure relates to a curved plate and to a method of forming a curved plate. In particular, the present disclosure relates to a curved plate having two superposed layers and to a method of forming the same.
2. Discussion of the Related Art
Bimetal plates are relatively small plates having two or more layers formed of different metals. For example, the metals have different thermal coefficients of expansion. Thus, under varying temperature conditions, the shape of the bimetal plate changes.
FIG. 1 illustrates an example of a curved bimetal plate 100 in two different states. The bimetal plate 100 comprises a first layer 102 of a first metal, and a second layer 104 of a second metal. The first and second layers have different thermal coefficients of expansion.
The bimetal plate 100 shown on the left in FIG. 1 assumes a temperature T1 of the plate, which is, for example, a temperature of around 50° C., and results in the bimetal plate adopting the form of an arch, its opposite ends 106 curving downwards, and a middle portion curving upwards.
The bimetal plate 100 shown on the right in FIG. 1 assumes a temperature T2 of the plate, which is, for example, an ambient temperature of around 20° C. resulting in the bimetal plate adopting the form of an inverted arch, its opposite ends 106 curving upwards, and its middle portion curving downwards.
Bimetal plates such as plate 100 of FIG. 1 may be used in a variety of applications, such as in thermostats or other forms of thermally activated switches. More recently, it has been proposed to use such elements in energy harvesters, which convert thermal energy into electrical energy.
A method that could be used to form a curved plate such as the bimetal plate 100 of FIG. 1 for example involves stamping two sheets of metal together in the desired form.
In certain applications, including in energy harvesters, it is desirable to provide curved plates of very small dimensions, in the order of tens of micrometers or even just a few micrometers. However, the stamping method indicated above is not adapted to fabricating curved plates having very small dimensions.